Feed mechanism for inked ribbon



May 18, 1965 I B. HOWARD FEED MECHANISM FOR INKED RIBBON Fild June 20, 1962 3 Sheets-Sheet 1 M I R A 0 W W v o m e A M m Wm m Q .m o H a N '47 fa /V6915 May 18, 1965 a. HOWARD FEED MECHANISM FOR INKED RIBBON 3 Sheets-Sheet 2 'Filed June 20, 1962 INVENTOR.

EEK/YARD mo n May 18, 1965 B. HOWARD FEED MECHANISM FOR INKED RIBBON 5 Sheets-Sheet 3 Filed June 20, 1962 United States Patent 3,184,tl27 FEED MEQHANISM FOR INKED RIBBON Bernard Howard, Upper Saddle River, NJ, assignor to Mite Corporation, New Haven, Conn, a corporation of Delaware Filed June 26, 1962, Ser. No. 203,768 18 Claims. (Cl. 19716l) An inked ribbon is commonly employed not only in typewriters, but in other printers such as telegraph printers used for communication over wire and radio channels, and in business machines and computers.

One object of the present invention is to provide a compact simplified reversible ribbon feed mechanism. A more specific object is to provide a ribbon feed mechanism adapted for use in a printer perforator and reader apparatus disclosed in my copending companion applica tions, Serial No. 203,785, filed June 20, 1962, and Serial No. 203,778, filed June 20, 1962.

The present improved ribbon feed mechanism includes the usual two ratchet wheels with their associated feed pawls and check dogs. However, the direction of ribbon feed is reversed by changing only the check dogs, while both feed pawls continue to operate. Inasmuch as the check dogs require no associated mechanism to recipro cate the same, it is relatively easy to make one check dog inoperative when the other is operative.

In accordance with a further and more detailed feature and object of the present invention the position of the check dogs is changed by a ribbon-end-sensing arm which is connected to the check dogs by an over-the-center spring, and the same spring is further employed as a means to urge the operative check dog toward its ratchet wheel.

To accomplish the foregoing general objects, and such other objects as may hereinafter appear, the invention resides in the ribbon feed elements and their relation one to another as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

FIG. 1 is a perspective view showing a tape perforator and reader with the cover removed;

FIG. lA is a schematic plan view in block form;

FIG. 2 is a schematic transverse section, with a combined page printer mounted over the tape machine;

FIG. 3 is a plan view of the ribbon feed mechanism used in the machine of FIG. 1;

FIG. 4 is a fragmentary view taken at the line 44 of FIG. 3; and shows a ribbon guide;

FIG. 5 is a partially sectioned elevation looking toward the right of FIG. 3; and

FIG. 6 shows one of the spool holding spindles in greater detail.

Referring to FIG. 1 of the drawing, a paper tape 24 is supplied from a large tape roll 26 disposed horizontally over the rear part of the apparatus. The tape is guided through a channel 2'7 and around an angularly disposed direction-changing idler 2S and thence over a type cylinder indicated at 34 The ink ribbon 32 extends trans versely of the paper tape. The ink ribbon is supplied from a conventional typewriter spool 94, and is wound up on another conventional typewriter spool 96 or vice versa. The spools are turned by ratchet feed mechanism which is not conventional. The ink ribbon is guided around rollers 33, 4t and 42. A print hammer (not shown) is located between the forward and rearward passes of the ink ribbon and serves to strike the lower pass downward against the paper tape and the type cylinder therebeneath. The paper is printed with the type at the back face of the paper.

The tape next passes through a perforator indicated generally at 44. The tape is given a row of small perice forations for a sprocket wheel feed, as well as main code perforations.

A length of the printed and perforated tape then is displayed, as shown at 45, over a support or track 48. The tape then extends downward and reversely upward to provide a slack loop of tape, indicated at 59. After passing around a tight tape sensing roller, the tape enters the tape reader, indicated at 52, where the code perforations are machine read. The tape leaves the machine at 54.

FIG. 1 also shows the manually operable keyboard, generally designated 56. This may he slid back beneath the main body of the apparatus, and for this purpose a release lever 53 is moved sideward to unlock the keyboard, thereby freeing it. FIG. 2 shows the forward position.

The keyboard section preferably includes two counters, the digit wheels of which are visible at 66 and 62 (FIG. 1). One of these is a counter to indicate the number of characters transmitted before signalling carriage return. The other window exposes digit wheels which may be preset by knob 63 to warn or signal the operator when a desired number of characters for a single line has been transmitted, the signal in this case being a lamp 6 which is lighted at the end of a line of desired length.

The switch panel 66 is provided with a considerable number of switches having handles 68 which may be moved to two positions. By appropriately operating these different switches in combination, the machine may be made to perform any one of a desired number of combinations of operations.

After printing an exposed length of tape, the operator may read the same to discover an error. On discovering an error, an error marking device 64 may be slid along its guide rod 69 until its pointer reaches the error, where upon the handle 64 is depressed. The device then functions to put an error perforation through one edge of the tape to notch the edge. With a wider tape it is a hole instead of a notch.

Referring to FIG. l-A, the box 500 represents the selector of my Patent 2,942,065 issued June 21, 1960, and has its main cam shaft 118 continuously driven by a motor 5&2 with built in reduction gearing at 5%, connected to shaft 118 through a pinion 566 and a gear 508 with an idler 51f therebetween. Motor 502 is a synchronous motor, and pinion 506 may be removed and replaced to provide operating speeds of 60, 66, and words per minute. The change in diameter of pinion 506 is accommodated by moving the center position of idler 51.0. These gears are also shown in FIG. 1.

Main shaft 118 is geared to the cam shaft 216 of the reader 5-2 by means of gears 218, 220, and 222. The printer perforator is driven from the special function shaft of the selector 5%. The keyboard (shown in FIG. 1 but not FIG. 1-A) also'has a cam shaft, as is fully described in my patent 2,977,413 issued March 28, 1961. The said shaft is driven from the gear 213, and for this purpose the keyboard has a gear 512 which moves into mesh beneath gear 218 when the keyboard is pulled to its forward or operating position. Gear 5-12 is disengaged from gear 218 when the keyboard is slid back to inoperative position.

Referring to FIG. 2 of the drawing, the printer, perforator and reader mechanism is housed in the area marked R. The keyboard 56 may be pulled out, as shown, but when pushed rearward it is located beneath the region R. The tape roll is located at 26. When a page printer is provided it is preferably located above the tap roll 26, as indicated at P. It is supplied with wide paper from a paper roll 25, the paper being fed upward, as indicated at 29, and then forward over the top of the page printer P, and thence downward and around a direction-reversing roller 31, and thence upward out of the machine at33.

The paper i printed on its way up from the roller 31. The page printer P may be the same as that disclosed in my patent 2,942,065. The entire assembly may be mounted on shock mounts, as suggested at 35.

FIGURES 3-6 show the feed mechanism for the ribbon spools 94 and 96 of FIG. 1. Referring to FIG. 3 there is a first spool holder 70 with a ratchet wheel 72, and a second spool holder 74- with a ratchet wheel 76. The ratchet wheels are so faced as to pull the ribbon on to their respective spools, that is, they oppositely faced so as to reverse the direction of the ribbon movement.

A feed pawl 78 cooperates with ratchet wheel 72, and for convenience of reference may be considered to be a forward feed pawl. A feed pawl 80 cooperates with the ratchet wheel 76 and may be considered to be a reverse feed palwl. There is a linkage 82, 84, 86 to reciprocate the feed pawls 78 and 80. Each feed pawl is disengaged near the end of its feed stroke, as described later.

There is also a check dog 88 for ratchet wheel 72, and a check dog 90 for ratchet wheel 76. In the present case these are formed integrally and are pivoted at 92, so that when one check dog, in this case the dog 88, is operative, the other is inoperative.

I have found that it is not necessary to disable the reverse feed pawl, in this case the feed pawl 80. This is so because only the spool 94, controlled by its operat-ive check dog 88, has a cumulative take-up action. The other spool 96 oscillates slightly, say the distance of a tooth on the ratchet wheel, and thus momentarily takes up a bit of the slack in the ribbon, but there is no cumulative feed, and consequently the ribbon is unwound from spool 96,.as it is wound on spool 94.

Considering the arrangement in greater detail, the feed pawls 78 and 80 are carried at the ends of a rocker arm 86, which is pivoted at 92. A spring wire 98 coiled about the pivot 100 of pawl 78 urges the pawl toward ratchet wheel 72. There is a similar spring wire 102 coiled about pivot 104 for pawl 80.

' The rocker arm 86 is connected at 104 to a link 84 which extends to an upright arm 82 (FIG. secured to a shaft 106 which is rocked or oscillated by the regular print mechanism in which the inked ribbon is being used.

'The feed stroke of the pawls might be varied by changing the effective radius of pin 108 relative to rock shaft 106. However, in the present case the adjustment is obtained by means of fixed adjustable eccentrics 110 (FIG. 3) and 112, against which the tails 114, 116 of the feed pawls hear.

The main purpose of the tail is to disengage or move the pawl outward toward the end of its feed stroke, and the eflective length of the feed stroke may be varied by moving the pawl outward sooner or later. This in turn depends onthe position of the abutment against which the tail bears, and that position is effectively varied by loosening a screw 11 1 holding the eccentric 110, and turning the eccentric, and then locking it again in its new position. The screw 11-1 is better shown in FIG. 5, but

for eccentric 112. The adjustment is usually for one ratchet tooth, but may be made for two or even three ratchet teeth.

In the present case the ink ribbon is used at a printing station located approximately at the numeral 118. The ribbon is led from spool 96 around guides 120, 122 and 124, thence to a slotted guide 126, and thence over the printing station to a direction reversing roller 128. The ribbon then goes back to the slotted guide 126 and passes around guides 130, 132 and 134, and so to the take-up spool 94.

For automatic ribbon reverse there is a somewhat T- shaped ribbon-end-sensing arm 136 having a ribbon slot 138 at one end, and a ribbon slot 140 at the other end. The arm is pivoted at 142. It is customary to provide a ribbon with a small eyelet or like projection near each end of the ribbon, and when this reaches ribbon slot 140 it carries the arm 136 with it, thus tilting the T-shaped 4 member from the position shown, to an opposite position which moves the lower end 144 of the stem of the T toward the right.

The .check dogs are formed integrally, and themselves constitute the cross bar of a somewhat T-shaped member having a short stem the end of which is shown at 146, the T .being inverted as viewed in FIG. 3. The paths of the ends 144 and 146 are adjacent one another, and the ends are connected by an over-the-center spring 150. This acts in compression, and its action is such that when the end 144 moves to the right, beyond the end 146, the end 146 is abruptly moved to the left, thereby making the check dog eifective and the check dog 88 ineffective.

With this arrangement the over-the-cen-ter spring 150 acts not only for that purpose, but also acts as a spring for normally urging either check dog against its ratchet wheel. The spring serves a dual purpose. I The ribbon guide 126 is shown in greater detail in FIG. 4, it being understood that the lower slot 152 receives the lower pass which is used at the printing station, and the upper slot 154 receives the upper pass of the ribbon. Both slots are open for easy insertion of the ribbon.

It will be understood that the spool holders have appropriate means to turn a spool and to hold it on the spindle. Referring to FIG. 6, the spindle 70 is riveted to fixed mounting plate 162 and carries ratchet wheel 72 with its sleeve-like hub 164, this being held on spindle 70 by a resilient split lock ring 166. The sleeve 164 has a convex spring 168 which bears against the inside of a ribbon spool and holds it in position. The ratchet wheel 72 has a pin 170 which enters a mating hole in a standard spool to insure rotation of the spool with the ratchet wheel.

Referring to FIG. 3, the adjustability of the abutments 110 and 112 is not essential. They need not be made in the form of eccentrics, although adjustment in that manner is convenient.. However, even if not adjustable, some form of abutment cooperating with a camming surface or tail on the. feed pawl, or more generally, some means to momentarily disengage the reverse feed pawl during part of its stroke, is important in the present arrangement in order that the reverse feed pawl not act as a check dog which might prevent unwinding of the ribbon. With the present arrangement the unused feed pawl 80 takes up a bit of slack of the ribbon during its feed movement, but the action is not cumulative, When the feed pawl 80 is momentarily disengaged near the end of its stroke, the ribbon again goes slack. Thus one feed pawl, in this case pawl 78, has a cumulative feed action because the check dog 88 is continuously in engagement with the ratchet wheel 72, while the other feed dog 80 has no cumulative action.

It is believed that the construction and operation of my improved ribbon feed mechanism, as well as the advantages thereof will be apparent from the foregoing description. It will also be apparent that while I have shown and described it in a preferred form, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims. In the claims the term oppositely facing ratchet wheel means merely that it would move the ribbon in opposite direc tion. The terms forward and reverse are relative to one another, rather than absolute.

I claim:

1. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with an oppositely facing ratchet wheel, a forward feed pawl cooperating with one ratchet wheel, a reverse feed pawl cooperating with the other ratchet wheel, linkage to reciprocate the feed pawls, means to disengage each feed pawl from its ratchet wheel near the end of its feed stroke, a check dog for one ratchet wheel, a check dog for the other ratchet wheel, and a ribbon reversing means so connected to said check dogs but not to said feed pawls as to make one check dog operative and the other inoperative while both feed pawls remain operative.

2. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with an oppositely facing ratchet wheel, a forward feed pawl cooperating with one ratchet wheel, a reverse feed pawl cooperating with the other ratchet wheel, linkage including a rocker arm to move the feed pawls in alternation, a check dog for one ratchet wheel, a check dog for the other ratchet wheel, and a ribbon reversing means so connected to said check dogs but not to said feed pawls as to make one check dog operative and the other inoperative while both feed pawls remain operative, and means to momentarily disengage the reverse feed pawl from its ratchet Wheel at the end of each feed stroke.

3. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with an oppositely facing ratchet wheel, a forward feed pawl cooperating with one ratchet wheel, a reverse feed pawl cooperating with the other ratchet wheel, linkage to reciprocate the feed pawls, means to disengage each feed pawl from it's ratchet wheel near the end of its feed stroke, a check dog for one ratchet wheel, a check dog for the other ratchet wheel, an arm carrying said check dogs at its ends and said arm being pivotedtherebetween, a ribbon-end-sensing arm, and means between thesensing arm and the arm carrying the check dogs to make one check dog or the other operative as may be appropriate, while both feed pawls remain operative.

4. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with an oppositely facing ratchet wheel, a forward feed pawl cooperating with one ratchet wheel, a reverse feed pawl cooperating with the other ratchet wheel, linkage to reciprocate the feed pawls, a check dog for one ratchet wheel, a check dog for the other ratchet wheel, an arm carrying said check dogs at its ends and said arm being pivoted therebetween, a ribbon-end-sensing arm with a ribbon slot whereby said arm is moved near the end of a ribbon, an over-the-center spring between the sensing arm and the arm carrying the check dogs to make one check dog or the other operative as may be appropriate, while both feed pawls remain operative, and means to momentarily disengage the reverse feed pawl from its ratchet wheel at the end of each feed stroke.

5. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with an oppositely facing ratchet wheel, a forward feed pawl cooperating with one ratchet wheel, a reverse feed pawl cooperating with the other ratchet wheel, linkage to reciprocate the feed pawls, means to disengage each feed pawl from its ratchet wheel near the end of its feed stroke, a check dog for one ratchet wheel, a check dog for the other ratchet wheel, an arm carrying said check dogs at its ends and said arm being pivoted therebetween, a ribbon-end-sensing arm with a ribobn slot whereby said arm is moved near the end of a ribbon, and an over-the-center spring between the sensing arm and the arm carrying the check dogs to make one check dog or the other operative as may be appropriate, while both feed pawls remain operative, said over-thecenter spring acting also as a spring for urging its check dog against its ratchet wheel.

6. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with a ratchet wheel, a feed pawl for each ratchet wheel, means to reciprocate said pawls, means to disengage each feed pawl from its ratchet wheel near the end of its feed stroke, an arm extending between said ratchet wheels and having a check dog at each end with a pivot therebetween, whereby one check dog is inoperative when the other is operative, and a somewhat T-shaped ribbon-end-sensing arm having a pivot at the middle, the end of the stem of said T-shaped arm being operatively connected to the dog-carrying arm to tilt the same, whereby hte direction of ribbon feed is reversed by the effect of the check dogs while both teed pawls remain operative.

7. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with a ratchet wheel, a feed pawl for each ratchet wheel, an arm extending between said ratchet wheels and having a check dog at each end with a pivot therebetween, whereby one check dog is inoperative when the other is operative, said arm constituting the crossbar of a somewhat T-shaped member, a somewhat T-shaped ribbon-end sensing arm having a pivot at the middle, the end of the stem of said sensing arm being disposed adjacent the end of the stem of the dog carrying member, an over-the-center spring connecting the adjacent ends of the stems, and means to momentarily disengage the reverse feed pawl from its ratchet wheel at the end of each feed stroke.

8. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with a ratchet wheel, a feed pawl for each ratchet wheel, means to reciprocate said pawls, an arm extending between said ratchet wheels and having a check dog at each end with a pivot therebetween, whereby one check dog is inoperative when the other is operative, said arm constituting the crossbar of a somewhat T-sh'aped member, a somewhat T-sha-ped ribbonend sensing arm having a pivot at the middle, the end of the stern of said sensing arm being disposed adjacent the end of the stem of the dog carrying member, an over-thecenter spring connecting the adjacent ends of the stems, whereby the direction of ribbon feed is reversed by the effect of the check dogs while both feed pawls remain operative, and means to momentarily disengage the reverse feed pawl from its ratchet wheel at the end of each feed stroke.

9. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet Wheel, a second spool holder with a ratchet wheel, a rocker arm extending adjacent both ratchet wheels and carrying a feed pawl at each end, means to oscillate said rocker arm to cause said pawls to reciprocate, another arm extending between said ratchet wheels and having a check dog at each end with a pivot therebetween whereby one check dog is inoperative when the other is operative, said arm constituting the crossbar of a somewhat T-shaped member, a somewhat T-shaped ribbon-end sensing arm having a pivot at the middle, the end of the stern of said sensing arm being disposed adjacent the end of the stem of the dog carrying member, an over-the-center spring connecting the adjacent ends of the stems, whereby the direction of ribbon feed is reversed by the eifect of the check dogs while both feed pawls remain operative, and means to momentarily disengage the reverse feed pawl from its ratchet wheel at the end of each feed stroke.

10. Feed mechanism for an ink ribbon or the like, said mechanism comprising a first spool holder with a ratchet wheel, a second spool holder with a ratchet wheel disposed near the first, a rocker arm extending adjacent both ratchet wheels and carrying a feed pawl at each end, means to oscillate said rocker arm to cause said pawls to reciprocate, means to disengage each feed pawl from its ratchet wheel near the end of its feed stroke, another arm extending between said ratchet wheels and having a check dog at each end with a pivot therebetween, whereby one check dog is inoperative when the other is operative, said arm constituting the crossbar of a somewhat T-shaped member, a somewhat T-shaped ribbon-end sensing arm having a ribbon slot at each end and a pivot at the middle, the end of the stem of said sensing arm being disposed adjacent the end of the stem of the dog carrying member,

and an over-the-center spring connecting the adjacent ends of the stems, whereby the direction of ribbon feed is reversed by the effect of the check dogs while both feed pawls remain operative, said over-the-center spring acting also as a spring for urging acheck dog against its ratchet wheel.

11. A feed mechanism as defined in claim 2, in which the means to momentarily disengage the reverse feed pawl comprises a camming surface on the feed pawl and a stationary abutment against which said camming surface bears during the movement of the feed pawl.

12. A feed mechanism as defined in claim 7, in which the means to momentarily disengage the reverse feed pawl comprises a camming surface on the feed pawl and a stationary abutment against which said camming surface bears during the movement of the feed pawl.

13. A feed mechanism as defined in claim 8, in which the means to momentarily disengage the reverse feed pawl comprises a camming surface on the feed pawl and a stationary abutment against which said camming surface bears during the movement of the feed pawl.

14. A feed mechanism as defined in claim 4, in which the means to momentarily disengage the reverse feed pawl comprises a camming surface on the feed pawl, and a stationary abutment against which said camming surface bears during the movement of the feed pawl, said abutment being held by a releasable screw adjustment of its position relative to the feed pawl.

15. A feed mechanism as defined in claim 9, in which the means to momentarily disengage the reverse feed pawl comprises a camming surface on'the feed pawl, and a stationary abutment against which said camming surface bears during the movement of the feed pawl, said abut- 8 ment being held by a releasable screw adjustment of its position relative to the feed pawl.

16. A feed mechanism as defined in claim 2, in which the means to momentarily disengage the reverse feed pawl comprises a tail'projecting from the feed pawl, and a stationary abutment against which said tail bears during the movement of the feed pawl, said abutment being an cecentric held in fixed position by a releasable screw for easy adjustment of its position relative to the tail.

17. A feed mechanism as defined in claim 4 in which the means to momentarily disengage the reverse feed pawl comprises a tail projecting from the feed pawl, and a stationary abutment against which said tail bears during the movement of the feed pawl, said abutment being an eccentric held in fixed position by a releasable screw for easy adjustment of its position relative to the tail.

18. A feed mechanism as defined in claim 8 in which the means to momentarily disengage the reverse feed pawl comprises a tail projecting from the feed pawl, and a stationary abutment against which said tail bears during the movement of the feed pawl, said abutment being an eccentric held in fixed position by a releasable screw for easy adjustment of its position relative to the tail.

References Cited by the Examiner j Zum Bahlen et al. 197-165 ROBERT E. PULFREY,Primary Examiner. V 

1. FEED MECHANISM FOR AN INK RIBBON OR THE LIKE, SAID MECHANISM COMPRISING A FIRST SPOOL HOLDER WITH A RATCHET WHEEL, A SECOND SPOOL HOLDER WITH AN OPPOSITELY FACING RATCHET WHEEL, A FORWARD FEED PAWL COOPERATING WITH ONE RATCHET WHEEL, A REVERSE FEED PAWL COOPERATING WITH THE OTHER RATCHET WHEEL, LINKAGE TO RECIPROCATE THE FEED PAWLS, MEANS TO DISENGAGE EACH FEED PAWL FROM ITS RATCHET WHEEL NEAR THE END OF ITS FEED STROKE, A CHECK DOG FOR ONE RATCHET WHEEL A CHECK DOG FOR THE OTHER RATCHET WHEEL, AND A RIBBON REVERSING MEANS SO CONNECTED TO SAID CHECK DOGS 